


Show Him How It's Done

by Destielshipper4Cas



Category: Supernatural
Genre: Alpha Dean, Alpha/Beta/Omega Dynamics, Barebacking, Bottom Castiel, Dorks in Love, Explicit Sexual Content, First Time, Getting Together, Idiots in Love, Jealousy, Loss of Virginity, M/M, Omega Castiel, Omega Verse, Pining, Roommates, Smut, Top Dean, Unsafe Sex, Virgin Castiel (Supernatural)
Language: English
Status: Completed
Published: 2019-08-14
Updated: 2019-08-18
Packaged: 2020-08-23 13:33:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,781
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20243683
Author URL: https://archiveofourown.org/users/Destielshipper4Cas/pseuds/Destielshipper4Cas
Summary: Virgin Cas needs some pointers on how to get properly turned on by alphas so that he can engage in sexual intercourse with the alpha he has been going out with for months. Dean does not approve of said alpha, but is happy to help his roommate, best friend, and long-time crush out, regardless.





	1. Chapter 1

**Author's Note:**

> Warning: It seems like cheating at first, but Cas and Balthazar are in an open relationship.

Ever since Cas had started going out with that alpha jerk, Balthazar, Dean was on edge even more so than usual. What kind of a stupid name was ‘Balthazar’ anyway? He definitely wasn’t good enough for Cas. His reputation for enjoying orgies preceded him, and he simply wasn’t a good fit for sweet, innocent Cas.

Living with his omega best friend he had a crush on had never been easy. After all, he had to see Cas walk from the bathroom to his own room with nothing but a towel wrapped around his waist, smell his delicious scent when they were watching a movie together on the couch… and don’t even get him started on how Cas’ smell changed when he was about to go into heat.

Point being—now that Cas was going out with that jerk, Dean’s frustration levels had skyrocketed. He had tried to let his alpha blow off some steam by fucking as many pretty omegas as he could charm into his bed, but then he started feeling guilty whenever he imagined it was Cas he was with.

This all brought him to the moment on a Saturday night when he was sitting on the couch in their living room instead of cruising for omega ass. For once, Cas wasn’t out with douchebag, either, but was currently sitting on the couch with him, their thighs occasionally brushing against each other when one of them moved.

They were on their second beer of the night, having one of their deep roommate conversations about… Wait, what was it they were talking about? Dean focused on what Cas was saying instead of innocuously staring at his pretty lips, and—yep. He was still going on about bees.

When Cas lapsed into silence, a forlorn expression on his face that Dean knew didn’t have anything to do with the diminishing bee population, Dean decided to be a good best friend and get to the bottom of what was bothering Cas.

“Okay, out with it,” he said, bumping him with his shoulder. “Why are you moping around?”

Cas looked at him, still surprised that, after all these years, Dean could read him with such ease, even when he tried to conceal that he was bothered by something to begin with.

“Believe me, you don’t want to know,” he mumbled, taking a big swig of his beer.

“Believe me, I _do_ want to know,” Dean replied promptly. “’Else I wouldn’t have asked.”

Cas sighed, looking down at his own hands, fiddled around with his bottle, and then, seemingly coming to a decision, faced Dean again.

“You know that I’ve been going out with Balthazar for a couple of months now.”

That was the moment Dean regretted that he had pressured Cas into confiding in him. He was barely able to hold back a growl because whenever he thought about Cas with Balth-ass, his alpha went ballistic.

Outwardly, he remained calm and nodded.

“Well, so,” Cas continued, “we want to… you know. And I have problems… you know.”

Cas made some vague hand gestures that could mean anything from brushing his teeth to grinding coffee beans.

When Dean raised his eyebrows at Cas, indicating that he’d have to elaborate, Cas quickly finished with, “…Getting aroused when I’m with someone else.”

The omega looked away again, a blush creeping up his cheeks.

Dean could relate. _That_ he had not expected and it was definitely making it into the top five of his list of uncomfortable conversations.

“Wow, okay. Seems like a problem you should discuss with your doctor,” he said, trying not to imagine Cas and Balthazar getting it on.

Cas shot him a dark look that Dean could easily read as, ‘_You _asked.’

“It’s not a medical issue,” Cas grumbled. “I’m doing just fine if I… if I’m alone, you know?”

Since pawning the conversation off on someone else hadn’t worked, Dean downed the rest of his beer as he racked his brain as to how he could help his friend. Then he put his empty beer bottle down onto the table.

“Okay. So…” He couldn’t believe he was going to ask this, but he soldiered on, “You have problems getting slick or hard?”

The blush was back on Cas’ cheeks, but he answered anyway, “Both.”

“And what’s different when you jerk off?” Dean asked.

“Masturbating is easy, I can just concentrate on myself. But when I’m together with someone, I’m just too… nervous.” Cas shrugged awkwardly, glancing at Dean. “I’m thinking about whether he likes what I’m doing. Should I use more tongue? Do I use too much tongue? And then when I don’t get slick, I get nervous about not slicking. It’s embarrassing for an omega, you know, because I won’t be slick enough for his knot or maybe not even enough for his penis.”

Dean swallowed hard around his suddenly dry throat. Cas—his innocent, virgin Cas, who never used four-letter words, had just said ‘masturbating,’ and ‘knot,’ and ‘penis’ without so much as blushing. Or not more so than before in any case.

“Dean, I swear to God, if you start laughing at me right now, I won’t talk to you again, ever!” Cas glowered at him, apparently having taken Dean’s gobsmacked expression the wrong way.

“No… I… just… penis!” Dean babbled, his voice unusually high, and then quickly cleared his throat when Cas narrowed his eyes at him. “So…” he said, his voice thankfully back to normal. “You’ve really never been aroused when you two have been making out?”

Cas shook his head and bit his lower lip, which made Dean look at the omega’s mouth for a moment before he shook his head and focused back on his eyes. His best friend was waiting for advice for being with his boyfriend, and here he was, ogling him.

“You should just let go, you know? Don’t be in your head so much, just enjoy the moment.”

Cas squinted at him and after a moment of silence, he said, “That’s all? Dean Winchester, sex expert. And all I get is ‘enjoy the moment’?”

Dean huffed. “What do you want me to say? I’m an alpha. I could give other alphas pointers on how to get an omega wet, but how should I know how things are working from your end?”

Again, Cas chewed on his own bottom lip, staring into space. Then he looked up determined and demanded, “Tell me what you would tell other alphas, then. Maybe I can use some of the pointers, too.”

Dean snorted. “I highly doubt it.”

“Dean, please.”

Dean sighed. He simply couldn’t resist Cas looking at him like that, pleading eyes, pouting lips... He was so gone for this omega.

0

Cas knew Dean couldn’t resist his pleading look, but he was ready to play dirty if need be. And right now, he really needed some advice or else he would stay a virgin forever. Besides, he’d never have a chance with an alpha as experienced as Dean if he didn’t know what he was doing when it came to sex.

“Okay,” Dean relented and Cas cheered inwardly. “So. It’s all about the anticipation, you know? For example, you might want to place a hand on his thigh.”

“Like this?” Cas asked eagerly as he put his beer bottle onto the table before putting his hand on Dean’s thigh. He always liked touching Dean, but he didn’t know what anticipation had to do with a hand on a thigh.

“No.” Dean shook his head and took Cas’ hand, laying it back into Cas’ lap. Then he turned towards Cas so they were facing each other. “Like this.”

With those words, Dean put his hand between them on the couch, his fingers just barely brushing against Cas’ thigh.

Somehow, Dean’s other hand had found its way to the back of his neck and he lightly played with Cas’ hair. For some reason, those innocuous touches sent goosebumps and shivers through Cas’ body.

“I’d keep intense eye contact,” Dean continued to explain, staring deeply into Cas’ eyes, and Cas couldn’t have looked away if he wanted to.

He could definitely see how that technique would work for Dean, with eyes as beautiful as his. Who would ever want to look away from them?

Dean’s fingers weren’t just brushing against Cas’ thigh anymore. Somehow, his hand was now on top of Cas’ thigh, inching higher ever so slowly.

When Dean licked his lips, Cas’ eyes were immediately drawn to the movement and he felt himself leaning in as if attracted by some magnet. Dean met him halfway and kissed his lips softly, just barely touching his lips against Cas’.

Dean was on him now, slowly lowering him down until he was lying on the couch while distracting him with those infuriatingly soft kisses.

Then the alpha suddenly stopped kissing him and continued to narrate, “Then, when I get him under me, I sometimes like to let my alpha out to play a little. See if his omega is into that.”

Before Cas could ask how he did that, Dean continued to demonstrate. First, he rubbed his cheek against Cas’ shoulder, neck, face, scent marking him.

“You can nose along his neck,” Dean explained. His voice had turned husky and when he continued, it was barely above a whisper, “Maybe graze his scent gland, see if you get him to submit.”

Cas instinctively bared his neck for better access.

“Tease his mating gland with a flick of your tongue. Make him wonder if it was an accident or deliberate.”

Cas moaned when he felt Dean nibble at his mating gland. Dean’s hand was still on his thigh and had inched even further up. When it grazed Cas’ erection, Cas did wonder if it had just been an accident or if it was part of Dean’s plan to drive him insane with lust.

For the first time in the presence of another person, Cas felt slick wetness between his cheeks.

He saw the exact moment Dean smelled the slick and for a moment, Cas thought he felt an answering erection press just above his own, but the next second, Dean was standing a few feet away from the couch.

While Cas was still reeling from what had happened and wondering if Dean had superspeed, Dean cleared his throat and said, “Doesn’t seem like you have a problem to me. All systems are a go. You’ll definitely be slick enough to take his knot. I’m gonna…” He pointed over his shoulder towards his room or maybe the bathroom and, apparently using his superspeed again, was gone the next second.

Cas was left behind, baffled. For a second there, Cas had been sure he had smelled alpha arousal, too. When the shower started, he briefly wondered if Dean was in there, taking care of his own arousal.

Back in his own room, the memory of Dean mouthing at his neck quickly brought him to orgasm.


	2. Chapter 2

The next time Balth-ass was over, Dean tried to distract himself. Still, martyr that he was, he didn’t leave the apartment or at least go into his room. No, he wanted to know when it was over so that he could get the details, because he apparently liked torturing himself, which was why he was sitting in the living room, watching TV and glancing towards Cas’ room ever so often.

The thought that that alpha jerk got to sleep with Cas made him grit his teeth and turn the volume of the TV up so that he at least wouldn’t have to hear the moans that would surely come out of Cas’ room sooner or later.

It couldn’t have been more than ten minutes when the door to Cas’ room banged open and both Cas and Balthazar stormed out.

It took everything Dean got to pretend he wasn’t interested in what was going on, and instead keep staring at the TV. Of course, he wouldn’t have been able to tell what the film was about if asked about it.

“It worked when I was practicing with Dean!” Cas yelled.

Great. Cas was so gonna get him into an alpha fight.

“Oh, it did, did it?” Balthazar asked as he looked over at Dean who tried his hardest to keep his eyes trained on the TV.

“Yes! Right, Dean? Tell him that I got hard _and_ slicked when we practiced.”

Dean finally stopped pretending to watch TV and looked up. “I don’t think he wants to hear about that, Cas.”

“Your alpha ‘roommate’ is right,” Balthazar said while stalking towards the front door. “Call me if you’re ever functioning like normal omegas do.”

With those words, he left the apartment, banging the door behind him.

Just at that moment, some beta on TV was having a laughing fit and Dean quickly turned off the TV.

“Wow. What an ass,” he said, motioning towards the closed apartment door.

Cas sighed. “No, he’s right.” He wandered over and flopped down next to Dean. “I _am_ not working right.”

“What are you, a machine?”

Cas ignored Dean’s remark and continued, “I was trying the hand on the thigh technique, you know? That you showed me?” Like he could forget! “Because that worked _great_ last time—but it didn’t work. What kind of an omega doesn’t slick when he wants to have sex? He was right to call me dysfunctional.”

“No, he wasn’t and no, you aren’t. He was just angry. I mean… You just told him you cheated on him.”

“What?” Cas tilted his head and squinted at him. “I didn’t cheat on him.”

“You don’t necessarily have to have _sex_ with another person for it to count as cheating,” Dean explained because he had obsessed over what had happened between them the other night on the couch—this very couch, as a matter of fact—and he would not let Cas tell him that that had been nothing. Had _meant_ nothing.

Cas, for his part, was shooting him a dark look. “I know that. We were in an open relationship, doofus.” When Dean just gaped at him, he added, “What? You thought he would have gone out with me for two months if he hadn’t been allowed to sleep with other omegas in the meantime?”

Dean shook his head disbelievingly. “Why were you even _with_ that douchebag?”

Seriously. Cas deserved _so_ much better!

“Because,” Cas said, averting his eyes. “I heard that Balthazar liked having sex with… y’know. People like me.”

Dean furrowed his brows, unable to follow what Cas was saying. “Awesome omegas?”

Rolling his eyes, Cas corrected him, “Virgins, Dean.”

“Oh.”

“So I knew he wouldn’t mind my inexperience, and I would… you know… finally not be the ‘geeky virgin’ anymore.”

This conversation had just gotten interesting. It seemed like Cas hadn’t really been in love with douchebag to begin with and now they were broken up, anyway.

Dean licked his lips. “If that’s your goal, I can help with that,” he said, giving Cas his most flirty come-hither look that usually got him laid.

Cas, of course, only reacted by furrowing his brows in confusion, so Dean decided to take the more direct approach and put a tentative hand on Cas’ thigh.

“Oh,” Cas sighed, and then quickly added, “Don’t be disappointed if I don’t slick because…”

“Cas!” Dean interrupted him. Then he lowered his voice and whispered in his best seductive voice, “Get out of your head and just enjoy.”

“Okay, I… O-okay,” the omega stuttered, his breath hitching when Dean’s mouth found that spot again that had driven Cas crazy the last time.

Dean couldn’t believe his luck. He could touch Cas all over without feeling guilty. With that thought in mind, Dean pushed his hand under Cas’ shirt to feel more skin, grazing softly against his nipples and feeling them bud in response to his touch.

He let his mouth wander from Cas’ neck to his lips, nibbling at them and swallowing Cas’ moans eagerly. At the same time, he slid his hand underneath Cas’ waistband, teasing his cock with feather-light touches.

When the smell of slick filled the air, Dean grinned. Cas was such a responsive omega. Teasing slick out of him wasn’t only easy—it was _fun_.

With Cas’ help, he had the omega naked and kneeling on the couch in no time. Cas was grabbing onto the back of the couch for balance while he was presenting for Dean. Slick was trickling down the omega’s thighs and Dean couldn’t resist—he _had_ to have a taste of that.

At the first touch of Dean’s tongue to his virgin hole, Cas tensed slightly, probably having expected Dean’s cock.

“God, you taste so good!” Dean moaned and buried his face in Cas’ cheeks again so that he could start eating him out in earnest.

Cas’ sexy moans spurred him on even more, especially when the omega started writhing. With one hand, Dean reached between Cas’ legs so that he could fondle Cas’ balls and tug on them a little to encourage him to cum.

Slick came gushing out of Cas’ hole and Dean felt his balls hot and heavy in his hands. Then Cas moaned, “Dean!” and came all over the back of the couch.

Dean quickly slipped a finger into Cas’ hole to make sure he was as wet and loose as he seemed, then he got up, kissed the back of Cas’ neck, and slowly pushed inside of him.

Cas could do nothing but whimper and push back a bit, but he was too fucked out to be of much help.

“I got you,” Dean promised and nestled his nose into the crook of Cas’ neck, deeply inhaling the scent that drove his alpha crazy.

Cas bared his neck immediately, and Dean gave his mating gland a quick nibble before pushing into Cas a bit more, penetrating him fully. Cas let out a sexy moan and tried again to fuck back onto his cock.

Dean was so turned on that he only managed to thrust a few times before he felt his knot start to form. Careful not to push into Cas too roughly, he fucked into the omega a few more times, fucking broken moans of pleasure out of him, until Dean felt his balls tingling and knew that he wouldn’t be able to stop the hot rush of cum much longer. Careful not to push his knot into the omega’s hole, Dean let the orgasm wash over him, pumping his cum into his omega.

He placed another kiss to Cas’ shoulder blade and then pulled out. Slick mixed with semen was running down Cas’ thighs and even though Dean just wanted to flop down and cuddle up to Cas, he went to the bathroom to get a wet towel for Cas. An alpha had to take care of his omega, after all.

When he came back, Cas had already put on his shirt again and he was sitting on the couch, a few silent tears streaming down his face.

Dean’s stomach dropped. He had never made an omega cry before. And Cas wasn’t just any omega, he was _his_ omega.

He put the towel on the table and carefully sat down next to Cas, conscious of the fact that he was still very much naked, but at least Cas wasn’t wearing any pants, either. (They might have to get a new couch, though.)

“Did I hurt you?” Dean asked, not sure if he was allowed to hug Cas or if he should keep his distance.

“No, you idiot,” Cas said, angrily wiping away his tears. “We didn’t do much that could have hurt me. You didn’t even knot me.”

Since Cas didn’t enlighten him as to why he was crying, Dean took another guess. “Balthazar was an asshole. You shouldn’t be sad because of him.”

“That’s not why I’m upset, you assbutt.”

“I’m not sure if I like your new use of pet names, sweetheart,” Dean replied.

Cas punched him in the arm, but there was hardly any strength behind it. The corner of his mouth twitched into a small smile, though, so Dean counted that as a win.

“Do I have to keep guessing or…” Dean asked, trailing off to let Cas take over.

“It’s stupid,” Cas said.

He fell silent again, but Dean was good at waiting him out, and after a while, Cas finally started talking, “Everyone knows that Dean Winchester only ever sleeps with the same omega once. I just... Not that I thought we would… But in my fantasies—when we slept together, we’d end up knotted in bed and… I mean… I loved what we did, but I’m a bit sad we didn’t get to have _real_ sex, that’s all.”

Wow, that was… In _his_ fantasies? Cas had fantasized about them together? Dean realized that he probably shouldn’t have a silent freak-out when his omega was sitting there, looking miserable and waiting for him to say something.

“Okay, first of all, babe? That _was_ real sex,” Dean explained, putting an arm around him, pulling him close and placing a kiss on his head because if he had understood Cas correctly, he _was_ allowed to hug and kiss and do all those things. “Doesn’t get any realer than that. You’re officially not a geeky virgin anymore, congratulations.”

He smiled at Cas, trying to lighten the mood, but when Cas didn’t return the smile, he continued, “For me, it was better than any ‘real knotted sex’ I’ve ever had. And I didn’t knot you because we haven’t talked about it and I didn’t know if you wanted me to. But I would love to, next time.”

Cas looked up at that, eyes wide, searching Dean’s face for something.

“You do know that you’re not just any omega to me, right? If it’s up to me, I’d like to show you all kinds of ways we can get you to slick.”

He winked at Cas, and then, remembering that Cas probably still felt vulnerable and maybe wasn’t susceptible to his flirting at the moment (or ever), turned serious again.

“But we can start off with the ‘in bed’ part of your fantasies,” he suggested.

Cas was still looking at him as if he was searching for answers. Oh, right. This was Cas. He didn’t do innuendos or subtlety. Even though Dean sucked at articulating his feelings—for Cas, he just might have to make an exception.

“I, for one, would like to go cuddle for a bit with my omega in my bed. If he’ll have me?” he asked.

The answering smile on Cas’ face was totally worth the effort of expressing his feelings.

**Author's Note:**

> I would absolutely love to hear from you in the comment section. 
> 
> **[Here's the tumblr link for reblogging purposes](https://destielshipper4cas.tumblr.com/post/187667743954/azcadelja-blog-show-him-how-its-done-on-ao3)**.


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